public class Main {
    public static void main(String[] args) {
        System.out.println("Hello world!");
    }
}
class Solution {
    public int findPeakElement(int[] nums) {
        int left = 0,right = nums.length-1;
        while (left<right) {
            int mid = left + (right - left) / 2;
            //二段性
            if (nums[mid]>nums[mid+1]) {
                right = mid;
            } else if (nums[mid]<nums[mid+1]) {
                left = mid + 1;
            }
        }
        return left;
    }
}